X0306 4 2022-01-31 0 0001656634 Gritstone bio, Inc. GRTS 0001754470 Hawryluk Matthew C/O GRITSTONE BIO, INC. 5959 HORTON STREET, SUITE 300 EMERYVILLE CA 94608 0 1 0 0 See Remarks Common Stock 2022-01-31 4 A 0 21612 0 A 53351 D Stock Option (Right to Buy) 5.46 2022-01-31 4 A 0 129675 0 A 2032-01-30 Common Stock 129675 129675 D Represents Restricted Stock Units ("RSUs") which vest on the first anniversary of the grant date. Each RSU represents a contingent right to receive one share of common stock of the Issuer. Includes 12,139 shares of common stock purchased under the Issuer's Employee Stock Purchase Plan in a transaction exempt from Section 16(b) pursuant to Rule 16b-3(c) and 31,412 RSUs which vest over time measured from the grant date. One forty-eighth (1/48th) of the shares initially subject to the option will vest on each monthly anniversary measured from January 31, 2022 (the "Vesting Commencement Date"), so that 100% of the shares subject to the option will be fully vested and exercisable as of the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued service through each vesting date. Executive Vice President and Chief Business Officer /s/ Rahsaan Thompson, Attorney-in-Fact for Matthew Hawryluk 2022-04-20